Hepatitis B Virus (HBV)_B

Status: 
Ready to upload
Record number: 
1836
Adverse Occurrence type: 
MPHO Type: 
Estimated frequency: 
The article, based on multi-year analysis of blood donation in South Africa, estimates HepBsAg frequency of ~ 1 in 20,000 in donors, and transmission risk of 1 in 2.9 million using individual donation nucleic acid testing for HBV.
Time to detection: 
The donor was detected positive for HepBsAg and NAT on subsequent donation, and trace forward revealed symptomatic infected RBC transfusion recipient 84 days after transfusion. There may have been another transmission from this donation, however it is unknown as the platelet recipient was transfused but unit was untraceable.
Alerting signals, symptoms, evidence of occurrence: 
Recipient 28 years old male who received transfusion after car accident, had clinical signs and symptoms consistent with hepatitis.
Demonstration of imputability or root cause: 
The transfusion transmission was confirmed through sequencing. Donor had undetected infection as was in eclipse period for NAT, and no risk behaviors were uncovered. The donor was HepBsAg negative for months after becoming viremic, so possibly could have donated multiple infected units had NAT not been implemented.
Imputability grade: 
3 Definite/Certain/Proven
Suggest references: 
- Vermeulen M, et al. Hepatitis B virus transmission by blood transfusion during 4 years of individual-donation nucleic acid testing in South Africa: estimated and observed window period risk. Transfusion. 52(4):880-92, 2012 Apr. - Ryanne W. Lieshout-Krikke, et al. Rare transmission of hepatitis B virus by Dutch donors with occult infection. Transfusion 2016 Mar;56(3):691-8
Note: 
I would suggest removing the Ryanne study from reference as it refers to Dutch data not connected with the South Africa study - ok done (EP)
Expert comments for publication: 
The article alleges that the modeled risk of transfusion transmission of HBV using ID-NAT for screening is 73 fold higher than the observed risk based on one reported transmission. However, this assumes that all transmission events are recognized clinically and reported. This is unlikely. Also note that one unit from the infected donation was not traced, so the risk is likely at least double the estimate.